发布后显示用户名(php/mysql)

<?php
// 连接数据库
$servername = "localhost";
$username = "your_username";
$password = "your_password";
$dbname = "your_database";

$conn = new mysqli($servername, $username, $password, $dbname);
if ($conn->connect_error) {
    die("连接数据库失败: " . $conn->connect_error);
}

// 处理表单提交
if ($_SERVER["REQUEST_METHOD"] == "POST") {
    $username = $_POST["username"];
    $content = $_POST["content"];

    // 将数据插入数据库
    $sql = "INSERT INTO comments (username, content) VALUES ('$username', '$content')";
    if ($conn->query($sql) === TRUE) {
        echo "评论发布成功";
    } else {
        echo "发布评论时出错: " . $conn->error;
    }
}

// 查询评论列表
$sql = "SELECT username, content FROM comments";
$result = $conn->query($sql);

if ($result->num_rows > 0) {
    // 输出每条评论
    while($row = $result->fetch_assoc()) {
        echo "用户名: " . $row["username"]. "<br>";
        echo "评论内容: " . $row["content"]. "<br><br>";
    }
} else {
    echo "暂无评论";
}

$conn->close();
?>

<!-- HTML表单 -->
<form method="post" action="<?php echo $_SERVER["PHP_SELF"]; ?>">
    用户名: <input type="text" name="username"><br>
    评论内容: <textarea name="content"></textarea><br>
    <input type="submit" value="提交">
</form>